mitchell



(No Model.) 2 Sheets-Sheet 1.

J. MITCHELL. .l

FURNAOE. 1 No. 415,679. Patented Nov. 19. 1889.

(No Model.) 2 SheetsSheet 2.

J. MITCHELL.

FURNACE.

No. 415,679. Y Patented Nov. 19, 1889.

n. PETERS. Phom-Lnnognpher, Waihington, 0v 0.

UNITED STATES. PATENT OEEIcE.

JOHN MITCHELL, OF ROCHESTER, NEYV YORK, ASSIGNOR TO THE CLARKS COKING AND SMOKELESS FURNACE COMPANY, OF-SAME PLACE.

FURNACE.

SPECIFICATION forming part of Letters Patent No. 415,679, dated November 19, 1889.

Application filed February 11, 1889. Serial No. 299,486. (No model.)

To all whom it may concern: Be it known that I, JOHN MITCHELL, of Rochester, county of Monroe, State of New York, have invented an Improvement in Ooking Furnaces, of which the following description, in connection with the accompanying drawings, is a specification, like letters on the drawings representing like parts.

This invention relates to furnaces of that class in which soft or bituminous coal is 0011- sumed, and wherein the volatile products freed from the coal are ignited and a maximum amount of heat obtained from a minimum amount of coal.

'Prior to my present invention I am aware that furnaces provided with a boiler have been constructed in which the soft or bituminous coal is consumedin a coking-oven within the said furnace, the said coking oven being provided with a top arch or roof and with a fine connecting the said coking oven with the ash-pit of the main combustion-chamber.

Vith the furnaces constructed as above described the heat generated in the coking-oven is confined therein by the top arch or flue of the said oven, so that the said heat is caused to pass through the fines into the main combustion-chamber before being brought in contact with the boiler to be heated.

One feature of my present invention consists in constructing the coking-ovens as will be described, whereby the boiler is exposed to the dircctaction of the heat in. the cokingoven.

Another feature of my invention consists in a novel construction of hearth by which the said walls of the coking-ovens are protected from intense heat, therebyprolonging the life of the same.

My invention therefore consists, essentially, in the furnace provided with gratebars, a boiler supported by said furnace, a transverse wall a, and a wall 0,, extended to the said transverse wall and forming a coking-oven and a combustion-chamber, a wall or slab in the combustion-chamber to form a passage 1), a flue or passageb in the wall a to connect the coking-oven with the passage 1), and an exit-flue in the transverse wall, substantially as will be described.

Other features of my invention will be pointed out in the claims at the end of this specification.

Figure 1 in section and elevation shows a furnace provided with a boiler and embodying my invention. Fig. 2 is a longitudinal section of the furnace shown in Fig. 1, taken on line :10 00, Fig. 1.; Fig. 3,51 transverse section of the furnace shown in Fig. 1, taken. on'line y y; and Fig. 4, a transverse section of the furnace shown in Fig. 1, taken on line 2 z.

The furnace-walls A, sustaining the boiler A, may be of any usual or well-known construction.

The furnace is provided at its rear end with a transverse walla and is divided longitudinally by walls a into two coking-ovens (i one at each side of the furnace, and a central chamber a Each coking-oven (L3 is provided substantially near its center, as herein shown, with a bridge-wall of, extended to the bottom of the furnace and supporting one end of grate-bars a having their other ends supported, as shown,by the front plate a of the furnace. Below the grate-bars c is formed an ash-pit a", to which access may be had by a door a in the front end of the furnace, the side wall of the said ash-pit (marked a) forming the lower front portion of the side wall a of a coking-oven, the ash-pit wall a being made wider than that portion of the wall a above the grate-bars, for apurpose to be hereinafter described.

Each side wall a at the rear end of the furnace forms with the transverse wall a a fine or passage 1), which connects the coking-oven a with a central chamber h, (see Fig. 4,) formed by one or more slabs Z1 supported by the walls a. and extended from the wall a to the bridge-wall (E. The side walls a. of the ash-pit support grate-bars 17 (see Fig. 4,) the said grate-bars and slab dividing the central spaces between the coking-oven into two chambers b b.

The transverse wall a forms with the rear wall of the furnace a 'flue or passage b and the said transverse wall is provided with an opening to connect the chamber 6 with the said flue or passage, the said opening being controlled by a suitable damper b, which is herein shown as operated by a handle 12 at spectively, and to the chamberb through the 'door 0 The side wall a of each coking-oven, at its front end or at the grate-bars a, is preferably made of independent slabs or blocks cl, arched to form a passage or opening d, through which a gaseous flame from the coking-oven may pass into the central chamber 19 It wil'l be noticed that the boiler A forms, as it were, the roof of the coking-ovens and 3 of the central chamber 17 the side walls a of i the said coking-ovens being extended -to the said boiler and serving as a support for the boiler supported by said furnace, a transsanie at its under side within the furnace.

7 In the operation of my improved furnace the soft or bituminous coal or other material to be consumed is placed on the grate-bars within the coking-ovens a and ignited. The airto support combustion is admitted through the doora of the ash-pit a" of the cokingoven and passes up through the grate-bars and throughthe material thereon, carrying with it the volatile products of the coal liberated by the heat generated by the lowerlayer or portion of the coal resting upon thegratebars. The volatile products pass through the opening bin the Wall a into the flue or passage 1)" below the slabs Z1 and the grate-bars, and thence up through the grate-bars into the chamber or passage b where they meet the gaseous flame issuing from the cokingovens through the openings (1 and are consurned, the products of combustion passing from thecham-ber b through the opening-in the transverse wall a into the passage or flue bi and "thence through the boiler totlhe chimney, the valve or damper I) being open. The heat {generated by the combustion of the vo'latileproducts at that point where the 'said volatile-products commi-ngle or meet with the gaseous flame is intense, and to remove the meeting-point of the two gases or flames from the arch-of the Wall a. the wall a is In'this manner the,

It will be noticed that the heat generated in the coking-ovens is not confined to its front end, but is distributed throughout the said ovens and comes in contact with the boiler throughout its length, thus increasing the efficiency of the furnace for the purpose of evaporation,aswell as obviating burning out of the sidewall of the coking-oven.

As substantially all the heat generated by the consumption of the bituminous coal in the coking-oven is utilized to heat the boiler, the draft, and thereby the intensity of the flame and of the heat generated in the furnace, may be regulated by the doors in the front wall of the furnace, and also by the valve or damper b".

I claim 7 1. The furnace provided with grate-bars, a

verse wall a, a wall a", extended to the said transverse wall and forming a coking-oven a combustion-cha|nber and having its- -firont lower portion made Wider than the main por- .tion'of the wallafla wall or s-lab in the 00mbustion-chamber to form-a passagebf, and a line or passage Z; in the wall a to connect the coking oven with the ;passageb",,-su-bstantiall'y as described.

The furnace provided withra bo'ileran'd -:a

transverse wall a, formi-ng, \V-llihlt wall of the furnace, *a fine or passage, combined with a walla to form coking-ovens a and acen-tral chamber,grate-bars in said cokingovens and central chamber, a Wallor slab todi-vide-said central space into chambers 6 I2 and passage b, connecting the coking-oven'with the chamber b,-a'n exit .fine =or passage in the transverse walLanda dam-per to controlsa'id exit-passage, I-substan tially as described.

In testimony whereof -I :have signed my name to this specification in the presence-of two subscribing witnesses.

il O'HN .MJ EGH ETIL.

-Witnesses:

P. K. HILL, L. MoCULLocH. 

